Herpetic Encephalitis and Development of Refractory Epilepsy as a Neurological Sequela

Herpetic encephalitis is an inflammation of the brain parenchyma caused by the Herpes simplex virus (HSV), characterized by sudden onset of neurological symptoms such as fever, headache, seizures, and cognitive deficits. It presents high morbidity and mortality when not diagnosed and treated early and frequently evolves with moderate to severe neuropsychiatric sequelae. A previously healthy 40-year-old male patient presented with a febrile illness on 12/21/2003 and, after 15 days, developed seizures, requiring hospitalization and subsequent transfer to the intensive care unit due to status epilepticus. After stabilization, he remained under neurological follow-up between 2004 and 2005 due to refractory epilepsy. In January 2007, he underwent electroencephalography and other examinations in preparation for a right corticoamygdalohippocampectomy, which later proved ineffective. He is currently followed on an outpatient basis for bilateral temporal lobe epilepsy, with daily seizures, loss of consciousness, retrograde amnesia, and impairment of frontotemporal functions. The described case represents severe herpetic encephalitis, with difficult diagnosis and management, progressing to status epilepticus. The absence of viral agent identification hampers early diagnosis, which occurs in 70% of cases. Despite instituted therapy, the patient had persistent epileptic seizures, requiring continuous neurological follow-up and further investigation. The seizures were attributed to residual brain injury, resulting in an epileptic focus. Currently, the patient remains under outpatient neurological care, with persistent cognitive deficits and seizure activity. Despite polypharmacy with lamotrigine, quetiapine, valproic acid, cannabidiol, clobazam, and levetiracetam, focal impaired-awareness seizures remain pharmacoresistant. The presented clinical case highlights the severe neurological consequences resulting from HSV infection, even with appropriate therapeutic measures. Difficult-to-control epilepsy and permanent cognitive impairment emerged as consequences of the severe viral condition. Thus, the study reinforces the need for effective diagnostic and therapeutic strategies, as well as prolonged support for patients affected by this condition, aiming to minimize sequelae and promote quality of life.